Oxygen sensor calibration

Abstract

An example device includes processing circuitry configured to receive, from an oxygen sensor, an ambient air signal indicative of an oxygen partial pressure of ambient air. The processing circuitry is further configured to receive, from an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure. The processing circuitry is configured to determine, based on the atmospheric pressure sensor signal, an oxygen partial pressure of the ambient air, determine, based at least in part on the oxygen partial pressure of the ambient air and the ambient air signal, the one or more calibration parameters, and calibrate, based on the one or more calibration parameters, the oxygen sensor. The calibrated oxygen sensor may be used to, for example, determine the oxygen content of urine of a patient to monitor renal function of the patient.

What is claimed is: 
     
       1. A method comprising:
 receiving, by processing circuitry and from an oxygen sensor, an ambient air signal indicative of an oxygen partial pressure of ambient air; 
 receiving, by the processing circuitry and from an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure; 
 determining, by the processing circuitry and based on the atmospheric pressure sensor signal, the oxygen partial pressure of the ambient air; 
 determining, by the processing circuitry and based at least in part on the oxygen partial pressure of the ambient air and the ambient air signal, one or more calibration parameters; 
 calibrating, by the processing circuitry and based on the one or more calibration parameters, the oxygen sensor; 
 receiving, by the processing circuitry and from the oxygen sensor, a signal indicative of an oxygen partial pressure of a fluid; and 
 determining, by the processing circuitry and based on the signal indicative of the oxygen partial pressure of the fluid and the one or more calibration parameters, a calibrated oxygen partial pressure of the fluid. 
 
     
     
       2. The method of  claim 1 , wherein determining the calibrated oxygen partial pressure of the fluid comprises:
 determining, by the processing circuitry, the oxygen partial pressure of the fluid based on the signal indicative of the oxygen partial pressure of the fluid; and 
 applying, by the processing circuitry, a function to the determined oxygen partial pressure of the fluid, wherein the function is based on the one or more calibration parameters. 
 
     
     
       3. The method of  claim 2 , wherein the function is an offset. 
     
     
       4. The method of  claim 1 , further comprising:
 receiving, by the processing circuitry and from a temperature sensor, a temperature sensor signal indicative of a temperature of the ambient air, 
 wherein the one or more calibration parameters are further based on the temperature sensor signal. 
 
     
     
       5. The method of  claim 1 , further comprising:
 receiving, by the processing circuitry and from the oxygen sensor, an analyte signal indicative of an oxygen partial pressure of an analyte, 
 wherein the one or more calibration parameters are further based on the analyte signal. 
 
     
     
       6. The method of  claim 5 , wherein the analyte is nitrogen or carbon dioxide. 
     
     
       7. The method of  claim 5 , wherein the oxygen sensor is located in a gas tight container when sensing the oxygen partial pressure of the analyte. 
     
     
       8. The method of  claim 5 , wherein determining the calibrated oxygen partial pressure of the fluid comprises:
 determining, by the processing circuitry, the oxygen partial pressure of the fluid based on the signal indicative of the oxygen partial pressure of the fluid; and 
 applying a function to the determined oxygen partial pressure of the fluid, wherein the function is based on the one or more calibration parameters, and the one or more calibration parameters are further based on the analyte signal. 
 
     
     
       9. The method of  claim 8 , wherein the function comprises a linear function. 
     
     
       10. The method of  claim 8 , wherein the function is based on a Stern-Volmer relationship. 
     
     
       11. A device comprising:
 a memory configured to store one or more calibration parameters; and 
 processing circuitry communicatively coupled to the memory, the processing circuitry being configured to:
 receive, from an oxygen sensor, an ambient air signal indicative of an oxygen partial pressure of ambient air; 
 receive, from an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure; 
 determine, based on the atmospheric pressure sensor signal, the oxygen partial pressure of the ambient air; 
 determine, based at least in part on the oxygen partial pressure of the ambient air and the ambient air signal, the one or more calibration parameters; and 
 calibrate, based on the one or more calibration parameters, the oxygen sensor, 
 receive, from the oxygen sensor, a signal indicative of an oxygen partial pressure of a fluid; and 
 determine, based on the signal indicative of the oxygen partial pressure of the fluid and the one or more calibration parameters, a calibrated oxygen partial pressure of the fluid. 
 
 
     
     
       12. The device of  claim 11 , wherein as part of determining the calibrated oxygen partial pressure of the fluid, the processing circuitry is configured to:
 determine the oxygen partial pressure of the fluid based on the signal indicative of the oxygen partial pressure of the fluid; and 
 apply a function to the determined oxygen partial pressure of the fluid, wherein the function is based on the one or more calibration parameters. 
 
     
     
       13. The device of  claim 12 , wherein the function is an offset. 
     
     
       14. The device of  claim 11 , wherein the processing circuitry is further configured to:
 receive, from a temperature sensor, a temperature sensor signal indicative of a temperature of the ambient air, 
 wherein the one or more calibration parameters are further based on the temperature sensor signal. 
 
     
     
       15. The device of  claim 11 , wherein the processing circuitry is further configured to:
 receive, from the oxygen sensor, an analyte signal indicative of an oxygen partial pressure of an analyte, 
 wherein the one or more calibration parameters are further based on the analyte signal. 
 
     
     
       16. The device of  claim 15 , wherein the analyte is nitrogen or carbon dioxide. 
     
     
       17. The device of  claim 15 , wherein the oxygen sensor is configured to sense the oxygen partial pressure of the analyte when the oxygen sensor is located in a gas tight container. 
     
     
       18. The device of  claim 15 , wherein as part of determining the calibrated oxygen partial pressure of the fluid, the processing circuitry is configured to:
 determine the oxygen partial pressure of the fluid based on the signal indicative of the oxygen partial pressure of the fluid; and 
 apply a function to the determined oxygen partial pressure of the fluid, wherein the function is based on the one or more calibration parameters, and the one or more calibration parameters are further based on the analyte signal. 
 
     
     
       19. The device of  claim 18 , wherein the function comprises a linear function. 
     
     
       20. A device comprising:
 a memory configured to store one or more calibration parameters; and 
 processing circuitry communicatively coupled to the memory, the processing circuitry being configured to:
 receive, from an oxygen sensor, an ambient air signal indicative of an oxygen partial pressure of ambient air; 
 receive, from an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure; 
 determine, based on the atmospheric pressure sensor signal, the oxygen partial pressure of the ambient air; 
 determine, based at least in part on the oxygen partial pressure of the ambient air and the ambient air signal, the one or more calibration parameters; 
 calibrate, based on the one or more calibration parameters, the oxygen sensor; 
 receive, from the oxygen sensor, a signal indicative of an oxygen partial pressure of urine; and 
 determine, based on the signal indicative of the oxygen partial pressure of the urine and the one or more calibration parameters, a calibrated oxygen partial pressure of the urine.